Wireless receiving circuits



2 192 v 16245185, Apnl 7 H. J. ROUND WIRELESS R'EGEI'VING CIRCUITS Filed May 21. 1923' HENRY JQSEPH ROUND 951 his (1H0 40-1 M 4 4 Patented -Apr. 12,1927.

UNITED STATES PATENT orrlca HENRY JOSEPH ROUND, LONDON, ENGLAND, ASSIGNOB 'IO RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE.

I wmnnnss RECEIVING omcurrs.

Application filed. m 21, 1923, Serial No. 640,291, and in Great Britain ma 31,1922.

This invention relates to wireless receiving circuits of the type in which a crystal,

such as carborundum requiring an auxiliary potential is employed as the detector.

According to this invention a high resistance is employed in series with a cell or cells in place of the otentiometer which has hitherto been emp oyed and the resistance and the cell are shunted by a con- '0 denser.

My invention is illustrated by the accompanying diagram of the connections a crystal receiving set. The aerial circuit A is coupled to an oscillatory circuit 0 which I is connected to a carborundum crystal (.3 and a telephone T between which there are connected a high resistance R and a dry cell or cells B. The resistance may be, say, 100,000 ohms or more. K is a condenser shuntin the resistance and cell for allowing hig and low frequency oscillations to pass with low impedance.

This arrangement has the advantage that owing to the resistance the current from the cell is very small and therefore the life of the cell is considerably lengthened, and in addition to this it is found that practically all crystals of the same composition are in adjustment with the same resistance that no adjustments are necessary when a new crystal is inserted.

Having described my invention what I claim is ing, an antenna circuit, a recelving circuit coupled thereto, .a crystal detector associat- 1. A wireless receiving circuit compris-' ed with said receiving circuit, a resistance of the order of 100,000 ohms in series with said crystal detector, a battery connected in series with said resistance, said battery tor a condenser adapted to pass both audio and radio frequency currents shunted around said resistance and battery and means for receiving the detected signals from said receiving circuit. f

2. A wireless receiving circuit compris ing, an antenna circuit, a receiving circuit coupled thereto and adapted to be tuned to a desired frequency, a carborundum crystal detector associated with said receiving-air cuit, a resistance of the order of 100,000 ohms in series with said detector, a\bias1ng battery for said detector connected serially with the opposite side of said resistance, a condenser adapted to by-pass both audio and radio frequencies shunted around said resistance and. battery, and telephonic means for receiving the detected signal from said receiving circuit.

HENRY JOSEPH ROUND.

serving as a biasing means for said detec- 

